Simon Schenk wrote:
> ...how should I prevent - in a distributed, uncontrollable environment
> like the Web - the owner of u2 from adding a view based on u to u2
> tomorrow?
You don't have to.
If u2 is grounded then either the new view relates u2 to the same graph
in which case the triple is true, or to a different graph in which case
it is false.
In the latetr case (falsity), the named graphs approach to provenance
and trust then encourages you to rethink which sources you trust
Jeremy